This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Background: The NIA set aside program maintains aged rhesus monkeys at several facilities to provide for allocation to NIA-funded investigators. The current census of the NIA colony at TNPRC is 45, which is comprised of Indian-origin rhesus macaques of both sexes ranging in age from 17.83 to 25.85 years of age. Methods: The animals are housed among their breeding colony cohorts in several enclosures or they are pair housed with a compatible conspecific in indoor housing. Results/Discussion: Since November 2002, 68 animals have been shipped to affiliate investigators. Additionally, in the last year, tissues from five animals were sent to support NIA-supported programs.